While knowledge of alcohol use in the general adolescent population is expanding, there is limited empirical data on clinical samples of teen abusers and even less is known about the long term outcome of these teens. Unfortunately, the majority of teens who enter alcohol and drug treatment programs have a history of failure to attend school, suspension or expulsion and consequently, the results of studies from junior and senior high schools cannot be generalized to teens in treatment. Further, there is a plethora of treatment outcome studies involving adult alcoholics, but only recently has the clinical course of alcohol abuse begun to be explored for adolescents following treatment. The present study utilizes findings from adult alcoholism treatment outcome studies, cross-sectional and longitudinal studies of teens in the general population and information on distinctive features of adolescent abusers in treatment to predict the drinking and drug use outcome of adolescents 2 and 4 years following treatment. This study is an extension to 4 years of the current NIAAA 1 year follow-up of 250 abusing teens who have completed treatment. Studying this well characterized sample through periods of late adolescence and young adulthood may provide useful information regarding the degree to which abuse continues into early adulthood and deterrents to chronic abuse. To highlight the specific aims of this proposal, we will: 1) Examine the alcohol and drug treatment outcome for 250 teens at 2 and 4 years following treatment for alcohol and drug abuse, 2) Determine predictors of longer term (2 & 4 year) alcohol and drug use outcome and 3) Determine changes in learned behaviors (e.g., expectancies and coping strategies) which are associated with more successful functioning following treatment as well as neuropsychological status.